Solve the system of equations -x-y=3−x−y=3 and 6x+2y=-306x+2y=−30 by combining the equations.

One-third of the people from country a claim that they are from country b, and the rest admit they are from country a. one-fourth of the people from country claim that they are from country a, and the rest admit they are from country b. in a combined census of the two countries, one-half of the total claimed to be from a. what is the ratio of the populations of country a to that of country b.

What is the volume of this square pyramid?

If a baby uses 15 diapers in 2 days, how many diapers will the baby use in a year?